Solubility of Various Forms of Strontium Titanate in Lungs

Abstract

At the In-Tank Precipitation Facility of the Savannah River Site, strontium and other radionuclides are removed from high-level radioactive waste and sent to the Defense Waste Processing Facility. Strontium removal is accomplished by adsorption using a slurry that includes monosodium titanate, which forms strontium titanate with unknown lung solubility characteristics. The purpose of this study was to determine the solubility of strontium titanate in the form created at the In-Tank Precipitation facility. An in vitro dissolution study was done with a slurry simulant and with several types of strontium titanate, and the results were compared. An in vivo study was also performed with high-fired SrTiO3 in rats. Strontium and titanium were measured by inductively-coupled plasma/atomic emission spectrometry. The data from both studies were used independently to assign the compounds to an absorption type based on criteria specified in ICRP 71. Results of the in vitro studies showed that the Defense Waste Processing Facility simulant should be assigned to Type M and the strontium titanate should be assigned to Type S. Results of the in vivo study verified that SrTiO3 should be assigned to Type S. Lung clearance data of SrTiO3 from rats showed that 85% cleared within the first 24 h and the remaining 15% cleared with a half-time of 130 d. The initial rapid clearance is attributed to deposition in airways as compared to the alveolar region.

Bioactive SrTiO3 Nanotube Arrays: Strontium Delivery Platform on Ti-Based Osteoporotic Bone Implants

“…During the first 2 weeks, 5.2 μg of Sr is released from 1 cm 2 of the surface, and in the subsequent 2 weeks, the release amount is about 3.3 μg/cm 2 . The measured dissolution rates from SrTiO 3 have the same order of magnitude as that reported in ref . According to ref , Ti and Sr do not dissolve congruently.…”

ICRP Publication 134: Occupational Intakes of Radionuclides: Part 2

“…Excretion was predominantly faecal, indicating that the material was relatively insoluble. In-vitro dissolution tests performed with various forms of 90 SrTiO 3 from high-level radioactive waste facilities (Anderson et al ., 1999) showed that 97% of the strontium remained undissolved at 181 d, indicating assignment to Type S. Absorption parameter values calculated here were f r = 0.009, s r = 0.7 d −1 , and s s = 1.2×10 −4 d −1 . In a parallel in-vivo study, the biokinetics of strontium and titanium were followed for 30 d after intratracheal instillation of stable SrTiO 3 in rats.…”

Dissolution of Functional Materials and Rare Earth Oxides into Pseudo Alveolar Fluid

“…These ingredients have acceleration or suppression effects on dissolution. Therefore, solubility measurement experiments using pseudo biological fluids have been performed to evaluate the solubility of many kinds of materials such as heavy metal compounds [8][9][10][11][12] , mineral dusts including asbestos substitutes [13][14][15][16] , soils 17) , radio active aerosols [18][19][20] and other low solubility materials [21][22][23] into biological fluid.…”